The present invention relates to a circuit breaker with a detachable electric contact, composed of a fixed part and of a movable part.
It is conventionally known to use, for example in electrical panels, current breakers composed of a fixed part which is permanently connected to the bars of the electric sower supply and distribution circuits.
The movable or removable structure of the breaker is connected to the fixed part of the breaker; the Dart accommodates, in a known manner, all the mechanisms for actuating and operating the breaker.
The provision of a fixed part and of a removable part which form the breaker has the advantage that for maintenance, inspection or replacement of the actuation mechanism it is possible to quickly uncouple the removable part, together with all the electrical and mechanical components, from the fixed Dart of the breaker, which is permanently connected to the electric power supply bars.
In conventional breakers, coupling and uncoupling between the fixed part and the movable part of the breaker currently occur with the aid of a C-shaped supporting structure which accommodates a plurality of mutually parallel laminae or plates arranged in a pack-like configuration, forming on the front side and on the rear side contact openings or jaws which allow electrical connection to the electric power supply and distribution bars.
The individual plates or laminae, arranged in a pack-like configuration, are supported by a supporting frame so that they can oscillate; in order to give the laminae of the jaws an elastic preloading, there is provided a set of springs which act on the individual laminae.
Conventional contacts which form connecting jaws and are constituted by a pack of plates or laminae, blanked in the shape of a jaw, and the preloading springs and the support constitute a constructive assembly which has a considerable weight and a certain constructive complexity. Work-intensive operations are also required for the assembly of the individual parts. Moreover, functionality, electrical behavior and most of all reliability of conventional jaw devices is unsatisfactory. Thus, for example, in the case of a considerable axial misalignment between the conducting bars of the fixed part and of the movable part, current flows only in some regions and not uniformly and evenly throughout the entire extension or width of the contact; dielectric phenomena also cause disturbances.
Another drawback which occurs in the above described conventional contacts is the plurality of different constructive elements required to provide the contact.